Hostname: page-component-cd9895bd7-dk4vv Total loading time: 0 Render date: 2024-12-26T03:21:13.938Z Has data issue: false hasContentIssue false

The Later Evolution of the Contact Binaries AP Leo, AK Her, AB And and AM Leo

Published online by Cambridge University Press:  12 April 2016

L. Li
Affiliation:
Yunnan Observatory, National Astronomical Observatories, CAS, Kunming, Yunnan Province, P. R. , China
Z. Han
Affiliation:
Yunnan Observatory, National Astronomical Observatories, CAS, Kunming, Yunnan Province, P. R. , China
F. Zhang
Affiliation:
Yunnan Observatory, National Astronomical Observatories, CAS, Kunming, Yunnan Province, P. R. , China

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

A detailed study of the periods and light curves of binaries AK Her, AP Leo, AB And and AM Leo is presented. Based on the study of the O – C curves, we find that the period variation of each system contains several components with different frequencies, and we suggest that the periodical variations in the periods are likely influenced by different mechanisms. Based on the study of the light curve changes, we find that the light curves exhibit two kinds of variations: rapid variations and long-term variations. We investigate the physical mechanisms which may underlie the variations of the period and the light curve of each system and obtain some new conclusions. According to the characteristics of the rapid light variation in these systems, we suggest that the rapid change in the light curve is probably caused by pulsation of the common envelope, and that the mechanism(s) causing the pulsation may be mass transfer through the inner Lagrangian point L1 or its variation. Finally, the evolutionary trends of these systems are discussed, and we suggest that these systems may be progenitors of cataclysmic variables.

Type
Research Article
Copyright
Copyright © Astronomical Society of the Pacific 2002

References

Applegate, J.H. 1989, ApJ, 337, 865 Google Scholar
Applegate, J.H., & Patterson, J. 1987, ApJ, 322, L99 Google Scholar
Artiukhina, N.M. 1964, Perem. Zvezdy, 15, 127 Google Scholar
Binnendijk, L. 1970, Vistas Ast., 12, 217 Google Scholar
Demircan, O., & Derman, E. 1992, AJ, 103, 593 Google Scholar
Demircan, O., Derman, E., Akaiin, A., Selam, S., & Müyesseroğlu, Z. 1994, MNRAS, 267, 19 Google Scholar
Kalimeris, A., Rovithis-Livaniou, H., & Rovithis, P. 1994a, A&A, 282, 775 Google Scholar
Kalimeris, A., Rovithis-Livaniou, H., Rovithis, P., Oprescu, G., Dumitrescu, A., & Suran, M.D. 1994b, A&A, 291, 765 Google Scholar
Kraft, R.P. 1962, ApJ, 135, 408 CrossRefGoogle Scholar
Kraft, R.P. 1965, ApJ, 142, 1588 Google Scholar
Kraft, R.P. 1967, PASP, 79, 395 Google Scholar
Kraft, R.P., & Luyten, W.J. 1965, ApJ, 142, 1041 Google Scholar
Li, L., Zhang, F., & Han, Z. 2001, A&A, 368, 595 Google Scholar
Li, L., Zhang, F., & Han, Z. 2002, PASJ, 54, 73 Google Scholar
Matese, J.J., & Whitmire, D.P. 1983, A&A, 117, L7 Google Scholar
Meyer, E., & Meyer-Hofmeister, E. 1979, A&A, 78, 167 Google Scholar
Parimucha, S., Pribulla, T., & Vanko, M. 2000, IBVS, 4834 Google Scholar
Sahade, J. 1959, Mem. Soc. Roy. Sci. Liège, 5-ième Ser., 3, 76 Google Scholar